1. Field of the Invention
The present invention relates to a multiple-track recording magnetic head with a compact matrix structure.
2. Discussion of the Background
There is a recording magnetic head, known for example from the French patent application No. 88 05592, with a matrix structure, designed for multiple-track magnetic recording. A set such as this is formed by a dense network of magnetic micro-heads. This network has a set of substantially square-sectioned magnetic pads protruding outwards in a Cartesian matrix on a supporting substrate. The pads are generally formed by the grooving of a ferrite block. Conductors arranged in lines and columns are positioned in the grooves and are covered, or are buried in glass, and magnetic poles made of Sendust or a similar material are formed on the polished face of the grooves that are thus filled. These poles are all substantially parallel to one of the diagonals of the pads and, at each time, they join the facing corners of two pads, a narrow gap being made in the middle of these poles.
This head works suitably but, since it is necessary to form as many pads as there are micro-heads, the surface area occupied by the head is not used to the utmost efficiency.
The object of the present invention is a multiple-track magnetic head with compact matrix structure that makes it possible, for one and the same surface area of head, to have the greatest possible number of micro-heads, this result being achieved without any reduction in the efficiency of these micro-heads.
The multiple-track recording magnetic head with a compact matrix structure of magnetic heads, includes a matrix of pads made of a magnetic material protruding out of a supporting substrate made of magnetic material, and electrical conductors arranged in matrix form in the inter-pad spaces and covered with non-magnetic material. Each micro-head has a magnetic circuit formed by two neighboring pads. Part of the substrate joining the pads has poles made of material with high magnetic permeability formed on at least a part of the surface of each of these two pads which meet each other on non-magnetic material, substantially midway between the two pads, at a gap. Each magnetic pad is part of the magnetic circuit of four neighboring micro-heads, thus making it possible to have twice as many micro-heads as in known heads, for a total surface area of equal value.